CHANGELOG:
**New features**
Added new vignettes for multiple modalities. merging datasets and data projection
**Improvements**
Existing vignettes updated.
Improvements in `H5adReader`
Fixes in requirements due to jinja3 update that was breaking RTD builds
Fixes in `drop` in Metadata
Improvements in `show_zarr_tree` in DataStore that allow printing tree from any node and to any depth
Improvements in `plot_layout` in DataStore that allow shuffling and sorting of datapoints